function out = digitizebathy
% Interactively gather navigational chart soundings data
% To get data, first display the chart (e.g. a tiff file) in the plot windoww. 
% Then start function with:
%      out = digitizebathy
% or
%      out = [out; digitizebathy]   to continue building
%
% The function prompt for each depth value in the command window
% Output will be 3 columns of x,y,depth
%
%

i = 1;
h(i) = input('Enter depth of first point: ');
while h(i)~=999
    [x(i),y(i)] = ginput(1);
    hold on
    han = plot(x(i),y(i),'r*');
    set(han,'linew',2,'markersize',10)
    hold off
    % text(x(i),y(i),num2str(h(i)))
    i = i+1;
    disp('Enter depth of next point (999 to exit) ...')
    dep = input(['Press ENTER if same as last time (' (num2str(h(i-1))) '): ']);
    if isempty(dep)
        h(i) = h(i-1);
    else
        h(i) = dep;
    end
end
h(end) = [];
out = [x(:) y(:) h(:)];